1. Field of the Invention
The present invention relates to a quantization error compensation apparatus and a method thereof, and more particularly, to a quantization error compensation apparatus and a method thereof for adaptively compensating for an input brightness signal by using a brightness signal difference that is caused by the quantization of continuously input image signals
2. Description of the Related Art
Among the several methods for enhancing contrast of a displayed image, a histogram equalizing method has been widely used. Generally, since the histogram equalizing method provides an effect of stretching a dynamic range, it makes a flat gray distribution of an image and thus results in an enhancement of the contrast of the image. The known histogram equalizing method uses a transfer function that is obtained for each pixel independently, regardless of a correlation with a neighboring pixel. For example, pixel brightness levels 1 and 2 of an input image signal as shown in FIG. 1A are output to be brightness levels 0 and 3 as shown in FIG. 1B by a predetermined transfer function.
When an image signal is processed in the conventional histogram equalizing method, stripes (such as a contour line) are generated around a boundary where the correlation between the neighboring pixels is changed, thereby deteriorating the image quality.